Self closing diaphragm type valve with primary peripheral and secondary central openings

ABSTRACT

A valve, shaped and sized for metered dose inhalers, consisting of a mount, a central body and top plate with peripheral air passages and central opening for medication delivery. A flexible elastic diaphragm closes the air passages and a central wiper seal on the diaphragm isolates the center opening from the air passageway. Pressure on the rim of the central opening of the diaphragm causes it to open the air passages timed with injection of medication through the central opening.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is entitled to the benefit of Provisional PatentApplication Serial No. 60/135,563 filed May 24, 1999.

BACKGROUND—FIELD OF INVENTION

This invention relates to metered dose inhalers with the specific intentfor a reliable valve mechanism which will prevent inhalation of airuntil just prior to medication injection by the unit into the inhaledair stream without alteration of the medication spray in any way.

BACKGROUND—DESCRIPTION OF PRIOR ART

Millions of persons with asthma, chronic obstructive pulmonary disease,emphysema, and other pulmonary problems use metered dose inhalers forthe administration of nebulized medications of various types into theirlungs. Timing between the beginning of the inspiration of air to theinjection of the nebulized medication is critical. Injection ofmedication to late deposits the medication in the mouth and throat.Injection to early carries the medication into the smallest air sacs ofthe lung, the alveoli, which in most cases is not desirable. The correcttiming deposits the medication in the trachea, bronchi, and bronchioles.In all current metered dose inhaler units, there is an open breathingpassage around a medication canister which must be depressed, againstspring pressure, about 0.080 inches to begin medication injection,inspiration by the patient to begin at about 0.060 inches of movement.It is virtually impossible, even with training, to achieve perfecttiming. As a result, pharmacists speculate that up to 50% of medicationis wasted.

Devices such as described by Larson, et al, U.S. Pat. No. 5,598,836allow air leakage at all times. Actually, huge quantities of air can beinhaled through minute openings before the medication spray which is notdesired by pulmonary physiologists. The case is a complex mechanicaldevice with no protection for the canister, a highly specialized devicewhich would be expensive to manufacture and would require F.D.A.approval as a drug.

The mechanism of Hause, U.S. Pat. No. 5,904,139 is again a complexspecialized case with vent holes sealed by a plunger seal which is heldin place by either pressure of the internal spring mechanism of themedication canister, or by a separate spring which is placed above orbelow the canister which defeats the timing. The unit of Hause appearsnot to be reusable hence refill canisters, which are less costly thanwhole new units, could not be used. The unit would also appear to be noncleanable which is contrary to the desires of all manufacturers ofmetered dose inhalers and physicians prescribing them. It would alsorequire F.D.A. approval as a drug.

Another device of a whole different nature, a spring loaded means whichhas to be cocked, with a button to press that triggers the opening of aflap valve and depresses the canister, is a highly specialized,expensive to construct means with many parts to fail, and this has notbeen a popular addition to the field.

No prior art has been able to utilize the actuator cases that are now incommon usage.

SUMMARY

In accordance with the present invention, an insert valve comprises atubular mounting means, with a lateral opening for medication spray, acup like well holding a top plate with peripheral air passages and acentral opening for medication delivery means, said top plate extendingto the walls of the medication canister case and which by means of aflexible elastic diaphragm with a central opening and a wipe seal in thecup, prevents air passage until the medication canister is depressed,opening the air passages just prior to medication spray.

OBJECTS AND ADVANTAGES

Accordingly, several objects and advantages of my invention are aninexpensive, foolproof insert valve which can be molded to fit into anycommonly used metered dose inhaler actuators currently in use with rareexception. It will effectively time inspiration to medication injectioninto the inhaled air stream and is self closing, not relying on themedication canisters internal retracting means. It will allow themedication canister to be removed for complete cleaning of the actuator,the removeable flexible diaphragm being easily reinserted. It may beused with more than one refill medication canister further savingexpense. It does not allow leakage of air prior to activation, highlydesired by pulmonary specialists, nor does it in any way interfere withmedication dosage, plume velocity or shape, medication particle size, orair velocity around the medication spray. Another obvious advantage isthat the metered dose inhaler is not changed in appearance or use. Theuser depresses the canister top as he or she has always done.

DRAWING FIGURES

FIG. 1 is a cut away metered dose inhaler actuator with medicationcanister and insert valve in place. For clarity's sake the medicationcanister is shown higher above the diaphragm than in actual use.

FIG. 2 is a side view cross section of the valve in the resting or nonactivated mode.

FIG. 3 is a detail of the medication carrying tube inserted into acolumnar stem like pedestal projection from the metered dose inhalerbase with spray outlet and stop.

FIG. 4 is detail of the opening in the valve stem to allow medication tospray out.

FIG. 5 is an oblique exploded view of the valve with a cut awaydiaphragm.

FIG. 6 is an activated valve.

REFERENCE

NUMERALS IN DRAWINGS

11 case 12 canister chamber 13 mouthpiece 14 medication canister 15canister base 16 medication tube from canister 17 pedestal from base 18spray opening 19 stop 20 complete valve insert 21 top plate of valve 22air passages 23 walls of cup-like cavity 24 cavity 25 cavity base 26tubular wall of support 27 hole through support 28 spray opening 29flexible diaphragm 30 diaphragm central opening 31 tube part ofdiaphragm 32 wipe seal 33 medication cavity 34 pedestal tapered opening

DESCRIPTION—FIGURES 2,3,4,5,6—PREFERRED EMBODIMENT

A preferred embodiment of the present invention is illustrated in FIG. 2(side view, resting mode), FIG. 6 (side view, activated mode), and FIG.5 (oblique view). FIG. 4 shows a special feature of the tubular mountand FIG. 3 shows a medication carrying tube inserted into the pedestalbase of the actuator. FIG. 1 is to orient the valve with the totalmetered dose inhaler actuator or case. The insert valve consists ofthree sections. A tubular base 26 ( FIGS. 2,4,5, and 6) with angledbottom to match the mouthpiece (FIG. 1) 13 angle, the internal diameter27 of the tube to fit pedestal 17 has a cut out 28 (FIG. 4) to allowegress of medicine spray. The middle portion consists of a cup 24 withwall 23 and base 25 having a bottom central opening the same size as theinternal diameter 27 of the tubular base 26. The upper portion is aplate 21 shaped and sized to fit the canister containing chamber 12(FIG. 1) of the metered dose inhaler actuator or case. Circumferentialair passages 22 around the cup wall 23 are to the periphery of top plate21. A flexible, elastic diaphragm 29 of size to cover air passages 22rests on top plate 21 with a central tube like downward extension 31surrounding opening 30 and terminating in a bottom radial extension 32of such size so as to form a wipe seal along cup 24 wall 23.

Advantages

From the description above, a number of advantages for this valve insertbecome evident:

(a) this insert valve is simple in construction and principle, thereforereasonable to produce.

(b) the metered dose inhaler actuator units now in use need no change insize, shape, or configuration.

(c) there are no loose parts to inhale, the diaphragm being trapped inplace by the medication canister.

(d) it is not obvious, hence no visual cause for fear or anxiety byusers because of a change.

(e) use of the metered dose inhaler is exactly the same procedure as itwould be without the valve insert.

(f) in no way does it interfere with medication canister operation,medication dosage, spray velocity, spray plume size or shape, particlesize of medication, or air velocity surrounding the medication spray.

Operation—FIGS. 1,2,3,6

A metered dose inhaler actuator unit (FIG. 1) consists of a plastic case11, referred to as an actuator, with a medication canister chamber 12contiguous with a mouthpiece 13. From the floor of the mouthpiece 13arises a columnar pedestal 17 terminating at its upper end (FIG. 3) in atapered opening 34 into which the medication carrying tube 16, passingthrough diaphragm opening 30, from the medication canister 14 base 15 isjam fitted, its lower most position being maintained by stop 19. Themedication canister and base contain a spring loaded medication meteringand dispensing system.

The insert valve 20 (FIG. 1) is a jam fit on the pedestal 17 and a jamfit against the walls of the canister chamber 12. This effectivelycreates two chambers in the metered dose inhaler actuator. The valvediaphragm seals the circumferentially arranged air passages 22, the wipeseal 32 sealing the cup 24 wall 23, the pedestal 17 sealing the valvetubular base opening 27, and the medication carrying tube 16 sealing theopening 34, the medication channel 33 and spray opening 18 in thepedestal 17.

When a patient places his mouth over the mouthpiece 13, he cannotinhale, all air passages being blocked. As he presses the canister 14down, the canister base 15 (FIG. 6) contacts the inner circumference ofthe diaphragm 29 opening, moving it and wipe seal 32 down in cup 24,thereby lifting the outer circumference of the diaphragm 29 away fromthe valve top 21 and opening air passages 22. The patient is now able toinhale and with further downward movement of the canister, measured inthousandths of an inch and microseconds in time, the movement of thecanister 14 and canister base 15 down on medication carrying tube 16discharges medication down tube 16 into cavity 33 (FIG. 3) and out ofspray hole 18. Continued pressure down on the canister maintains the airpassages open to complete inspiration.

With release of pressure on the canister 14, its own internal springmechanism retracts the canister 14 and base 15 on the discharge tube 16.The elastic diaphragm 29 and wipe seal 32 move upward returning to theresting position in which the air passages 22 are closed. The cycle maynow be repeated.

The distance the canister and base move down on the discharge tube todischarge medication is minutely controlled so that the medication dosestays constant. This fixed discharge point is used to advantage in thatthe total height of the valve insert may be altered to allow timing,within reason, of the valve opening before medication spray so as tobest suit patient needs.

Conclusions, Ramifications, and Scope

Accordingly, the reader will see that the self closing insert diaphragmvalve with both peripheral and central openings for air flow andmedication delivery, is the only device which will fit inside thecurrently used metered dose inhaler actuators, completely innocuous, andwhich can divide the air flow passage into two distinct sectionsresponding to the normal use of the inhaler by timed opening of the airpassage to precede medication injection into the air stream at the besttime possible and without changing the usual use of the unit and withoutchanging medication dosage, spray velocity, spray plume size or shape,medication particle size, and air stream velocity around the medicationspray.

It is small, compact, easily and inexpensively produced, safe, and maybe used with canister refills. It allows the metered dose inhaler unitto be taken apart, cleansed, with easy reinsertion of the elasticdiaphragm with a finger tip so that the proper cleanliness may bemaintained.

The timing of inhalation to injection of medication is difficult foralmost everyone, especially the very young, and old so that 35-50% ofmost medication is wasted by not reaching the appropriate portions ofthe lung. This valve will reduce medication usage, waste, andsubsequently the cost to patient and insurers while giving the besttiming for inhaling medicine to allow the medication to reach the sitesin the lung where it is needed. Special programs set up to try to teachpeople how to use these units will no longer be needed. The totalfinancial saving should be substantial.

I claim:
 1. An insertable breathing control valve adapted for metereddose inhalers consisting of: a top plate, with or without peripheralseals, sized and shaped to so as to divide a metered dose inhaler intoan upper and lower chamber, said top plate having a cylindrical cup likedepression with a central bottom opening, an upper end and lower endbetween walls, said cup like depression being surrounded bycircumferentially equispaced inlet air ports in said top plate; saidcylindrical cup like depression having at the lower end a contiguoushollow stem with an opening, the opening in said hollow stem being of asize to fit over a metered dose inhaler pedestal snug and essentiallyair tight and of length to hold said top plate in proper position so asto divide a metered dose inhaler into upper and lower chambers, saidhollow stem having a side opening positioned so as to allow egress ofmedication spray; a diaphragm of elastic material capable of returningto an original shape and position, sized to cover said circumferentialequispaced inlet air ports, said diaphragm having a central stem likeextension of a diameter to freely move in said circular cylindrical cuplike depression of said top plate, said circular extension having alength to extend below a top surface of said top plate when saiddiaphragm is in a closed position, said central circular extensionhaving at a terminal end a circumferential lateral extension so as toact as a wipe seal against the walls of said cyindrical cup likedepression, both said diaphragm and said central stem like extensionhaving a central opening of a sufficient diameter to allow unrestrictedpassage of a medication dispensing tube, yet be small enough so that anupper circumferential edge of said central opening may be engaged by amedication canister base or spacer placed over a medication dispensingtube for the purpose of depressing a central portion of said diaphragm,thus opening said air inlet ports, thereby allowing inspiration timedwith delivery of medication.